Context: India has become the first country in the world to develop rice varieties using genome editing technology. Scientists have used Site-Directed Nuclease 1 and Site-Directed Nuclease 2 (SDN-1 and SDN-2) genome editing techniques to develop the seeds
The two new varieties give 25% more yield and use less water, and incorporate no foreign DNA. The new seeds will be available for farmers after the required clearances within six months and large-scale seed production will probably take place during the next three crop seasons.
Relevance of the Topic: Prelims: Regulation of Gene Editing in Agriculture; SDN technology (SDN1, 2, 3 etc.)
New genetically Edited Rice Varieties
- Scientists have developed two-genome edited, climate resilient, improved rice varieties- 'DRR Dhan 100 (Kamala)' and 'Pusa DST Rice 1' , after receiving appropriate bio-safety clearance under India's simplified regulations for genome edited crops.
- Developed by scientists from: Indian Agricultural Research Institute, New Delhi and the Indian Rice Research Institute, Hyderabad.
- Benefits of the New Varieties:
- Enhance production (25% more yield)
- Crop needs shorter time, and thus saves water used for irrigation
- Reduces greenhouse gas emissions (by 20%)
- Not GM Crop: The two new varieties incorporate no foreign DNA, so they are not genetically modified (GM). Hence the apprehensions about GM foods does not apply in this case.
India became the first country in the world to develop Genome-Edited (GE) Rice varieties. The new paddy varieties have the potential for revolutionary changes in higher production, climate adaptability, and water conservation.
Push For Genome Editing
- Under the budget announcement 2023-24, the government of India had allocated Rs 500 crore for genome editing in agricultural crops.
- ICAR has launched initiatives to harness genome editing for the development of many crops, including oilseeds and pulses, livestock, fish, and microbial varieties.
- Genome editing, particularly the CRISPR-Cas technology, is being hailed as a breakthrough in precision breeding. It enables scientists to make targeted changes in the native genes of living organisms, creating new and desirable traits without introducing foreign DNA.
- Two key approaches: Site Directed Nuclease 1 (SDN1) and Site Directed Nuclease 2 (SDN2) - produce genetically edited organisms that are considered indistinguishable from naturally occurring or conventionally bred mutants. They are exempt from the stringent bio-safety regulations under Rules 7-11 of the Environment (Protection) Act, 1986.
GE Rice Varieties: (Kamala and Pusa DST Rice 1)
- Scientists selected two widely cultivated mega rice varieties - Samba Mahsuri (BPT5204) and MTU1010 (Cottondora Sannalu).
- Samba Mahsuri is known for its fine grain quality and premium market value, but it falls short in terms of climate resilience. It is vulnerable to pests, diseases, and climate stress.
- MTU1010 is a high yielding early-duration variety (125-130 days) well-suited to Rabi season cultivation in southern India. But it too suffers from sensitivity to drought and soil salinity.
- Through genome editing, ICAR scientists enhanced these varieties with better stress tolerance, improved yield, and climate adaptability, without compromising their existing strengths, and developed two new varieties 'Kamala' and 'Pusa DST Rice 1'.
- Developed using the CRISPR-Cas9 system, these crops are free of foreign DNA and showcase impressive traits.
Note:
- Genetically Edited (GE) crops are different from genetically modified (GM) crops.
- GE crops involve mere editing of genes naturally present in the host plant, leading to mutation or changes in their DNA sequence. No foreign genes or DNA are incorporated.
- GM crops involve introduction of genes from unrelated species into host plants. E.g., genes from Bacillus thuringiensis (soil bacterium) in cotton crops.
Regulation of Gene Editing in Agriculture In India
- Genetically modified organisms (GMOs) are regulated in India by the ‘Rules for the Manufacture, Use, Import, Export and Storage of Hazardous Microorganisms/ Genetically Engineered Organisms or Cells, 1989’. The rules are notified under the Environment Protection Act 1986 to regulate GMOs.
- There is no explicit mention of the term gene editing. Recently, an amendment was introduced to the aforesaid regulation in order to encourage gene editing in agriculture.
- Gene editing techniquesusing native genome are allowed in India. However, gene editing techniques using foreign genomes are not allowed.
- Gene editing techniques called SDN 1 and 2 (Site-Directed Nuclease) use native genome and hence, are allowed under the Rules under EPA, 1986.
- Gene editing techniques using foreign genomes like SDN 3, 4 and 6 are placed under GMO regulation, and therefore not allowed in India.
Common types of Gene Editing Techniques:
- SDN-1: Site-Directed Nuclease (SDN) 1 is a site-directed mutagenesis (production of genetic mutations) without using a DNA sequence template. SDN1 introduces a precise cut in the DNA at the targeted location → the cell’s natural repair mechanisms fix these breaks without introducing any foreign genetic material.
- SDN-2: In SDN 2, the edit involves a precise cut in the DNA at a target location → a small template from the same species is provided to guide the repair process.
- SDN-3: Involves the insertion of foreign DNA and falls under the category of GMOs. E.g., Bt cotton → gene from the bacterium Bacillus thuringiensis (Bt) → inserted into cotton plants.
Development of these two varieties using genome-editing technology has paved the way of using this innovative method in other crops too for higher yields, climate resilience and improved quality.